SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1c17d933b958004cb8eb5690c0c246fc09291a4ec7f3d9eee9b0d25b145af5b' 
  AND token = 'Xmz8z48OWkUlo9CC1M0ZuRbFUUuMOdKGYhsVLAQx6eE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}